$ ./6.MY.translate.pl --configfile C --from tja --infile /home/bob/Documents/meditations/Algorithm-Markov-Multiorder-Learner-master/data/2.short.shelley.txt --outfile /home/bob/Desktop/1.state input is “The ancient teachers of this science,” said he, “promised impossibilities and performed nothing. The modern masters ... unfold to the world the deepest mysteries of creation. ---------------- begin block to change property is TO type is zilch expected type is zilch did execution get here? property is key type is zilch expected type is zilch did execution get here? property is FROM type is zilch expected type is zilch did execution get here? after block to change, self is bless({ format => 5.23, FROM => "en", key => 321, START => 1562878454, TO => "ru" }, "My::Module") in new, param_hr is { CONTENT => "\x{201C}The ancient teachers of this science,\x{201D} said he,\n\x{201C}promised impossibilities and performed nothing. The modern masters\npromise very little; they know that metals ... the steps\nalready marked, I will pioneer a new way, explore unknown powers, and\nunfold to the world the deepest mysteries of creation.\n\n", FROM => "tja", key => 123, TO => undef, } in new, self is bless({ format => 5.23, FROM => "en", key => 321, START => 1562878454, TO => "ru" }, "My::Module") in sub key akey is 123 you called key() method on object 'My::Module=HASH(0x56161e3a1cb0)' key() : changing key to '123' in sub key Use of uninitialized value $akey in concatenation (.) or string at ./6.MY.translate.pl line 62. akey is you called key() method on object 'My::Module=HASH(0x56161e3a1cb0)' my key: 123 --- mod is bless({ format => 5.23, FROM => "en", key => 123, START => 1562878454, TO => "ru" }, "My::Module") $